It is known in the art, in the production of replacement parts, support members and the like in the human body, to utilize a copy milling cutter in which a model is applied and sensed in the cutter and in response to the sensing a tool processes a blank in order to produce from the blank a body or a tool part with the same shape as the model.
Our Swedish patent application No. 9003967-8 corresponding to U.S. Ser. No. 805,955 describes a system in which the sensing or scanning of the model is separate from the processing equipment and control signals for the latter are generated with the aid of computer equipment.
The use of copy milling cutters has its limitations regarding production speed. Moreover, these is an additional disadvantage in that the read-off function and processing function must be located in the same premises. The appearance of the model is strictly linked to the structure of the copy milling cutter, which means that variations and additions to the shape of the model in question, enlargements of the contours and the like cannot be put into effect with the desired freedom of choice.
In connection with equipment in which it is desired that the sensing and processing functions be located in different premises, it is important that an expedient read-off function and processing of the thus obtained representation is effected. The representation and the control must be capable of co-ordination so that unambiguous scanning and sensing can be adapted to an optimum or to the greatest possible extent minimized control signal function.
The quantity of read-off data/information should be kept to a minimum so that the processing and selection functions in the computer equipment may be simplified/reduced while retaining the accuracy of control. The scanning and sensing principles and storage function in the data processing equipment are therefore of crucial importance in this context.
In the case when a telecommmunications medium (for example, communication via the public telephone network) is to be employed to transmit information from one place to another, it is vital that the quantity of requisite control signals can be reduced. In addition to operating with small scanning and processing quantities, it may be relevant to extract by means of data processing equipment characteristic parts of the read-off information and to transmit these characteristic parts via the medium, and also reconstruct replicas on the reception side with the aid of these characteristic parts so that sufficient control signals for the accurate control of the tool equipment can be obtained. In the scanning and sensing with contact devices/sensing signals, it is also essential for the shape of the position in the part co-operating with the contour relate to the shape of that part of the tool by means of which a blank is processed. An optimum relationship leads to significantly reduced read-off and processing information.
It is also esssential for the sensing and control functions to be related to one another without increasing processed data or information in the data processing equipment. A relationship between reading-in and reading-out of information entered in the computer must also be established in such a manner that, for example, the read-off function will be separated from the read-in function so that the processing function can be carried out more quickly than the read-out function.
The tool equipment must, for example in the production of dental implants, bridges, etc., be capable of working to a degree of accuracy/tolerance of one or a few hundredths of a millimeter, (for example, 0.01-0.09 mm). The resolution on scanning may in one embodiment (for example, scanning by laser) be appreciably greater, for example, one or a few thousandths of a millimeter.